Milking-machine pulsator.



A. W. REID.

MILKING MACHINE PULSATOR.

APPLICATION FILED on. 14. 1914.

l,15@ 452o- Patented Aug. 17, 1915.

An a 7w? I A. MRE/d .vation' of the complete pulsator.

amaxannnn. WALKER REID, or s'rnarronn, NEW ZEALAND.

MILKING-MACHINE PULSATOR.

Specification of Letters .Patent. Patented Aug.'1l 7, 19115..

' Application filed October 14, 1914. Serial No. 866,590.

To all whom it may concern:

Be it known that-I, ALEXANDER WALKER REID, subject of the King of Great Britain, residing at Stratford, New Zealand, have invented a new and useful Improved Milking-Machine Pulsator; and I do hereby declare the following to be a full, clear, and eXact description of the same.

This invention relates to an improved construction of milking machine pulsator for use in alternately connecting various parts of the machinery, and particularly the teat cups, with air and with a source of. vacuum.

The invention relates especially to that.

class of pulsator that is made automatic in its action through the agency of atmospheric air pressure caused by the connection of portions of the pulsator with vacuum, and in which a pair of cylinders are arranged in tandem and each provided with. a piston mounted therein, both of which pistons are attached to a slide valve that is adapted to be moved across a set of three ports by means of which a central vacuum port may be alternately brought into connection with each side port while the other is uncovered, and in which such reciprocation of the slide valve is brought about by alternately connecting the outer ends of the two cylinders with air and with the vacuum source, reversely to one another by the movements of the slide valve.

The invention consists in improved means whereby these alternate connections of the cylinder ends with air and with vacuum may be brought about in a simple and positive manner, and especially 'whereby'the change over in the connections shall be made quickly at the end of the pistons movements in each direction. 7

. In fully describing the invention reference will be made to the accompanying sheet of drawings, in which Figure 1 is, a plan, and Fig. 2 a front ele- Fig. 3 is a plan of the slide block showing the various ports therein. Fig. 4 is an underneath plan of the two slide valves used in this inventionand placed in their operative positions relative to one another. Fig. 5 is a sectional elevation taken on the line 55 ofFig. 3. Fig. 6 is a cross section taken on the line 6-6 of Fig. 3. Fig. 7 is an alternative detail that will be afterward more -:Eully referred to. A, A. are the two cylinders that are mounted in the same axial line on the re manner of connection allows of the piston rods being raised to free the slide valve,

Whenever desired, so that the pistons and .slide valve may be removed for attention or repairs of any kind. Each cylinder is closed at its outer end and is opened at its inner end and the pistons and piston rods are so adjusted that in their movements, when one piston is at the outer end of its cylinder, the other will be at the inner end of its cylinder.

The slide block B is provided with a set of three main ports arranged in a row thereon and the central one E of which is connected with the source of vacuum through a pipe connection E. The outer ports F and F are connected respectively with pipes G and- G that lead to-the teat cups or other appliances to be pulsated. The slide valve D at one limit of its movement is adapted to connect the central port E with the outer port on that side and to uncover the other outer port so that the reciprocation of the slide valve, will in the usual way, alternately connect the pipe F and F vwith the vacuum source and with air, so as to obtain the desired pulsations. The slide block is also formed with a second set ofthree ports arranged parallel to the main port. The central port H of this set is arranged in connection with the central port E of the main port's, through the bore H (Fig. 6), the passage through such bore into the port being controlled by a needle valve J. The two outer ports K and K are connected to the respective outer ends of the cylinders A and A" on the reverse sides of the slide block as shown by the dotted lines in-Fig. 3, through the small tubes M, M, that is the port K is connected to the-cylinder Aand the port K to the cylinder A. A second slide valve N is provided to reciprocate over B to engage that is attached to the frame and adjusting screw S the drawings, so that the air pressure upon the piston of the cylinder A is ready to act against the vacuum in the cylinder A and force both pistons and the main slide valve D across to the reverse position. At the other limit of movement, the slide valve N uncovers the port K and connects the port K with vacuum, so that the relative connections of the two cylinders A and A with vacuum and air are altered and the pistons and slide valve D caused to move back again. These movements of the slide valve N are obtained by the special means shown and are adapted to be made quickly and positively as the pistons and main slide Valve reach their limits of movement in each direction. These means consist of the tappet arms 0 and 0 extending horizontally from the respective ends of the main slide valve D and situated one on each side of the slide valve N, but with a distance between them sufiicient to allow for almost the full travel of the main slide valve without affecting the slide valve N. Each tappet carries a cylinder P extending longitudinally with the machine, and in each cylinder a helical spring R is inserted the outer end of which engages the adjacent side of the slide valve N. This slide valve is therefore held between the tappets and the spring cushions thus provided.

The slide valve N is held from any movement during the major portion of the main slide valves travel in each direction, by

means of a suitable spring detent, that will not give way under the force exerted by the compression of the springs R, caused by the travel of the main slide valve but which will give way when engaged by the tappet itself and then allow the spring that has been compressed, to force the slide valve over quickly to its other position, where it will be again retained until the slide valve moves to its limit in the reverse direction. The means shown in Figs. 1 and 2 for effecting these purposes consist of a spring arm S overlies the slide valve N and is provided with a tooth s on its underside. This tooth engages a round knob or projection n extending across the top of the slide valve and prevents the slide valve moving to either side until the pressure oi the main slide valve is exerted upon it, when the spring S will be forced upward and the knob n slide underneath the tooth s, quickly pushed over spring The tooth s will then dro down and engage the other side of the kno An is provided for regulatspring S.

the slide valve being then ing the tension of the Stops T the slide valve N at each limit of its movement and to prevent this slide valve l'rom being pushed too far-under the by the expansion of-the.

are arranged upon the slide block action of the springs R, or projections n (Fig. 1) may be made on the ends of the slide valve between which and the knob n' metal ball U that pro ects from the bottom end of a cylinder U mounted vertically upon the slide block. The ball iskept normally down by the compression of a spring S contained within the cylinder and the compression of which is governed by the set screw S threaded through the closed top end of the cylinder. The rate of operation of the pulsator is needle valve J which regulates the rate of the exhaustion of air from the cylinder ends through the pipes M and M, the ports K and K and the port and bore H. I

What I do claim as my invention, and desire to secure by Letters Patent is 1. In a milking machine pulsator the combination with a slide block formed with a series of three main ports therein, a pair of cylinders mounted one at each end of such slide block, pistons mounted within such cylinders having piston rods extending through attached to such pistons and adapted in its reciprocation to connect the central port with each of the outer ports in turn While uncovering the other outer port, a second series of three ports arranged in the slide block, the central one of which is connected with the central main, port, while the outer one on each side is connected with the outer end of the cylinder on the reverse side of the central port, and a second slide valve adapted to move across these latter ports and in its reciprocations to connect the central port with each of the outer ports in turn, while uncovering the other outer port, of tappet arms extending from the two ends of the main slide valve and passing one on each side of the second slide valve, spring cushions extending between the respective tappet arms and the said slide valve and yielding means whereby such slide valve maybe prevented from movement until engaged by the tappet arms of the main slide valve, substantially as specified.

2. In a milking machine pulsator having a pair of cylinders, pulsation pipes, a source of vacuum, double pistons mounted within the cylinders, a main slide valve operated by the double pistons and adapted alternately to connect the pulsation pipes with air and the source of vacuum, means for bringing the pistons alternately and reversely under the action of the vacuum, said means comprising a part having a series of governed by means of the spective tappet arms and the said slide valve, and yielding means forholding such slide valve from movement, substantially as specified.

3. In a milking machine pulsator, a main slide valve for causing the pulsations and a secondary slide valve for governing the movements of the main slide valve, tappet arms upon the respective ends of the main slide valve and extending on-the respective sides of such secondary slide valve, spring cushions in compression between both tappet arms and the slide valve between, and

means whereby the said slide valve may be held from movement until engaged by the tappet arms of the main slide valve and may then be released and pushed across by the expansion of the cushion spring compressed by the independent travel of the main slide valve, substantially as-specified.

4:. In a milking machine pulsator, a main slide valve for causing the pulsations, and a secondary slide valve for governing the movements of the main slide valve, tappet arms upon the respective ends of the main slide valve and extending across the respective sides of the secondary slide valve, spring cushions in compression between both tappet arms and the slide valve between, a spring detent bearing upon the top of said secondary slide valve and a knob or projection upon the top of said valve with which such spring detent engages, substantially as specified.

In'testimony whereof, I have signed this specification in the presence of two subscrib-- ing witnesses. v

ALEXANDER'WALKER REID;

Witnessesi I v W. ALEXANDER M. E. BROWN. 

